The superior aspect of the human shoulder is formed, in part, by the articulation of the lateral end of the clavicle with the acromion process of the scapula, forming the acromioclavicular joint--one of four joints which comprise the human shoulder The articular surfaces of the acromion process and the clavicle generally oppose one another with a cartilaginous articular disk sometimes being formed therebetween. Such articular disk, if present, partly and/or completely subdivides the space existing between the articular surfaces of the acromion process and the clavicle. The acromioclavicular ligament extends between the acromion process and the distal end of the clavicle, providing ligamentous interconnection therebetween. Further ligamentous stabilization of the distal clavicle and/or acromioclavicular junction is provided by a) the coracoacromial ligament which extends between the acromion and the coracoid process of the scapula, and b) the coracoclavicular ligament which connects the distal portion of the clavicle to the coracoid process.
The coracoclavicular ligament consists of two parts, the conoid ligament and the trapezoid ligament. These two portions of the coracoclavicular ligament are independently situated so as to resist upward movement of the clavicle and/or downward movement of the scapula and also to maintain proper anteroposterior alignment of the clavicle and scapula.
Injury to the acromioclavicular joint may result in stretching or disruption of one or more of the abovedescribed ligaments which stabilize the joint. Additionally, separation or disalignment of the clavicle and acromion may result in damage to or rupture of the relatively weak, flexible synovial capsule which surrounds the acromioclavicular joint. Such injuries often result in disruption of the normal anatomical alignment and positioning of the distal end of the clavicle relative to the acromion process.
Surgical intervention may be indicated in cases of severe traumatic rupture or tearing of the ligaments which stabilize the acromioclavicular junction. However, less dramatic injuries, such as stretching of the ligaments with or without concomitant damage to the synovial capsule, may be treated by non-surgical techniques aimed at restoring and maintaining proper alignment of the distal end of the clavicle with the acromion so as to permit natural healing of the ligaments, synovial capsule and/or surrounding tissues.
Non-surgical techniques heretofore employed in the treatment of acromioclavicular injuries have included a) taping of the shoulder with or without concomitant use of an arm-supporting sling and/or b) the application of one or more shoulder brace appliances known in the prior art.
Examples of shoulder brace appliances known in the prior art include the disclosures of U.S. Pat. Nos. 4,751,923; 4,784,128; 4,735,198; 4,785,803; 4,610,244; 3,906,944; 4,436,088; 4,644,939; 4,807,607; 4,446,858; 4,198,964 and 3,499,441.
Of particular note, the U.S. Pat. No. 4,198,964 (HONNEFFER) discloses a brace which is purportedly intended for treatment of acromioclavicular injuries. The HONNEFFER brace comprises a force-focusing member or shoulder pad positionable superior to the distal clavicle and attachable, by way of straps, to a) an arm sling and b) a body swathe or bandage member. The body swathe or bandage member fully wraps around the thorax and the upper portion of the involved arm. Thus, like many shoulder braces of the prior art, the HONNEFFER brace of U.S. Pat. No. 4,198,964 substantially immobilizes and impairs ROUTINE use of the involved arm. Furthermore, while some of the shoulder braces of the prior art may function to exert inferiorly directed pressure on the clavicle to correct superior displacement of the clavicle, none of these prior art braces are operative to exert anteroposterior pressure on the clavicle and/or acromioclavicular joint to correct anterior or posterior disalignment of the distal clavicle relative to the acromion.
In view of the shortcomings of the prior art there exists a need for an improved acromioclavicular brace or appliance capable of restoring and maintaining proper anatomical alignment of the acromioclavicular joint, including proper anteroposterior alignment thereof, while causing only minimal immobilization of the involved arm.